US7391746B2 - Power saving method in wireless LAN system for permitting terminal station to promptly transition to doze state by transmitting empty data frame - Google Patents

Power saving method in wireless LAN system for permitting terminal station to promptly transition to doze state by transmitting empty data frame Download PDF

Info

Publication number
US7391746B2
US7391746B2 US11/166,276 US16627605A US7391746B2 US 7391746 B2 US7391746 B2 US 7391746B2 US 16627605 A US16627605 A US 16627605A US 7391746 B2 US7391746 B2 US 7391746B2
Authority
US
United States
Prior art keywords
terminal station
base station
station
terminal
data
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related, expires
Application number
US11/166,276
Other versions
US20050286454A1 (en
Inventor
Shinichi Morimoto
Hideki Kurokawa
Youko Omori
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
NEC Corp
Original Assignee
NEC Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by NEC Corp filed Critical NEC Corp
Assigned to NEC CORPORATION reassignment NEC CORPORATION ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: KUROKAWA, HIDEKI, MORIMOTO, SHINICHI, OMORI, YOUKO
Publication of US20050286454A1 publication Critical patent/US20050286454A1/en
Priority to US12/109,536 priority Critical patent/US20080212508A1/en
Application granted granted Critical
Publication of US7391746B2 publication Critical patent/US7391746B2/en
Expired - Fee Related legal-status Critical Current
Adjusted expiration legal-status Critical

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W52/00—Power management, e.g. TPC [Transmission Power Control], power saving or power classes
    • H04W52/02—Power saving arrangements
    • H04W52/0209—Power saving arrangements in terminal devices
    • H04W52/0225—Power saving arrangements in terminal devices using monitoring of external events, e.g. the presence of a signal
    • H04W52/0235—Power saving arrangements in terminal devices using monitoring of external events, e.g. the presence of a signal where the received signal is a power saving command
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W74/00—Wireless channel access
    • H04W74/04—Scheduled access
    • H04W74/06—Scheduled access using polling
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
    • Y02D30/00—Reducing energy consumption in communication networks
    • Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks

Definitions

  • the present invention relates to a power saving method in a wireless LAN system, and more particularly, to a power saving method in a wireless LAN system conforming to IEEE802.11.
  • Power saving in a wireless LAN system conforming to IEEE802.11 is performed in sequences illustrated in FIGS. 1A , 1 B, for example, as disclosed in IEEE Std 802.11, 9.7 Frame exchange sequences Table 21 Frame sequence.
  • FIG. 1A is a sequence chart illustrating a sequence of operations when no data destined to a terminal station is stored in a base station.
  • the terminal station transmits PS-Poll, which is a control packet for prompting the base station to transmit data, to the base station for requesting the base station to transmit downlink data destined thereto after the terminal station has transitioned to an active mode, in which a transmission/reception function turns on (step 101 ).
  • PS-Poll is a control packet for prompting the base station to transmit data
  • the base station for requesting the base station to transmit downlink data destined thereto after the terminal station has transitioned to an active mode, in which a transmission/reception function turns on (step 101 ).
  • PS-Poll Upon receipt of PS-Poll without error, the base station transmits a successful reception notification signal ACK (step 102 ).
  • ACK Upon receipt of PS-Poll without error, the base station transmits a successful reception notification signal ACK (step 102 ).
  • the terminal station
  • FIG. 1B is a sequence chart illustrating a sequence of operations when data destined to the terminal station has been stored in the base station.
  • the terminal station transmits PS-Poll to the base station, after it has transitioned to the active mode, for requesting the base station to transmit downlink data destined thereto (step 111 ).
  • the base station Upon receipt of PS-Poll without errors, the base station transmits a data frame (step 112 ).
  • the terminal station Upon receipt of the data frame without errors, the terminal station transmits ACK (step 113 ).
  • the terminal station transitions to the doze state after it has completed the transmission of ACK.
  • FIG. 2 is a flow chart illustrating the operation of the terminal station in the foregoing situation.
  • the terminal station starts a receiving operation, it transitions to an active state (step 201 ).
  • the terminal station transmits PS-Poll to the base station for requesting the base station to transmit data destined to the terminal station (step 202 ).
  • the terminal station determines whether a response to PS-Pall from the base station is ACK or data (step 203 ). If the terminal station fails to receive either ACK or data, the terminal station again transmits PS-Pall (step 202 ).
  • the terminal station determines that there is no data destined thereto stored in the base station, and transitions to the doze state (step 205 ).
  • the terminal station transmits ACK to the base station (step 204 ), and transitions to the doze state (step 205 ), followed by termination of the receiving operation.
  • the base station when data destined to the terminal station is stored in the base station, the base station returns a data frame when it receives the PS-Poll signal from the terminal station without errors.
  • conventional general wireless LAN base stations are often configured to return ACK to a terminal station in response to PS-Poll from the terminal station irrespective of the presence or absence of data to the terminal station. This is because it takes long time to complete the transmission of the data frame so that the base station informs, as a temporary measure, the terminal station that the PS-Poll signal has been received without errors. IEEE802.11 also approves that ACK is returned.
  • FIGS. 3A , 3 B illustrate sequence charts when a base station returns ACK to a terminal station in response to PS-Poll from the terminal station irrespective of the presence or absence of data destined to the terminal station.
  • FIG. 3A is a sequence chart when no data destined to a terminal station is stored in the base station.
  • the terminal station transmits PS-Poll to the base station after it has transitioned to the active mode for requesting the base station to transmit downlink data destined thereto (step 301 ).
  • the base station Upon receipt of PS-Poll without errors, the base station transmits ACK (step 302 ).
  • FIG. 3B is a sequence chart when data destined to a terminal station is stored in a base station.
  • the terminal station transmits PS-Poll to the base station after it has transitioned to the active mode for requesting the base station to transmit downlink data destined thereto (step 311 ).
  • the base station Upon receipt of PS-Poll without errors, the base station transmits ACK to the terminal station (step 312 ).
  • the base station When data destined to the terminal station is stored in the base station, the base station further transmits a data frame to the terminal station (step 313 ).
  • the terminal station transmits ACK (step 314 ).
  • data communications in a power save mode in a general wireless LAN differs in a frame sequence chart between the terminal station and base station depending on the presence or absence of data destined to the terminal station stored in the base station.
  • the terminal station experiences difficulties in determining whether to transition to the doze state when no data is stored in the base station, resulting in difficulties in a reduction in power consumption. This is because the terminal station cannot determine the presence or absence of data destined thereto at the time it receives ACK, and therefore cannot promptly transition to the doze state.
  • the terminal station does not know whether or not data destined thereto is present in the base station at the time it receives ACK. Therefore, even if there is no data destined to the terminal station, the terminal station cannot transition to the doze state immediately after the receipt of ACK.
  • the base station upon receipt of a PS-Poll signal from a terminal station subordinate to a base station for prompting a transmission of data destined to the terminal station, transmits an ACK signal to the terminal station for indicating a successful reception of the PS-Poll signal, and also transmits a data frame including data destined to the terminal station when there is such data, or transmits an empty data frame when there is no data destined to the terminal station. Then, upon receipt of the data frame (including the empty data frame), the terminal station transmits an ACK signal to the base station, and then transitions to the doze state in which a transmission/reception function is made inoperative.
  • the base station performs the same operation in response to PS-Poll from the terminal station as the operation when data is stored therein, so that the terminal station can transition to the doze state after it has completed a sequential frame exchange procedure, thus making it possible to save the power in the terminal station.
  • FIGS. 1A , 1 B are sequence charts each illustrating a conventional power saving method in a wireless LAN system conforming to IEEE802.11, where FIG. 1A is a sequence chart when no data destined to a terminal station is stored in a base station, and FIG. 1B is a sequence chart when data destined to the terminal station is stored in the base station;
  • FIG. 2 is a flow chart illustrating a sequence of operations performed by the terminal station in the processes of FIGS. 1A , 1 B;
  • FIGS. 3A , 3 B are sequence charts each illustrating the operation of a base station when it returns ACK to a terminal station in response to PS-Poll from the terminal station irrespective of the presence or absence of data destined to the terminal station, where FIG. 3A is a sequence chart when no data destined to the terminal station is stored in the base station, and FIG. 3B is a sequence chart when data destined to the terminal station is stored in the base station;
  • FIGS. 4A , 4 B are sequence charts each illustrating a power saving method according to the present invention in a wireless LAN system conforming to IEEE802.11, where FIG. 4A is a sequence chart when no data destined to a terminal station is stored in a base station, and FIG. 4B is a sequence chart when data destined to the terminal station is stored in the base station; and
  • FIG. 5 is a flow chart illustrating a sequence of operations performed by the terminal station in the processes of FIGS. 4A , 4 B.
  • FIGS. 4A , 4 B illustrate sequence charts of a power saving method in a wireless LAN system conforming to IEEE802.11 in accordance with the present invention.
  • a base station returns ACK to a terminal station in response to PS-Poll from the terminal station irrespective of the presence or absence of data destined to the terminal station.
  • FIG. 4A is a sequence chart when no data destined to a terminal station is stored in a base station.
  • the terminal station transmits PS-Poll to the base station after it has transitioned to an active mode for requesting the base station to transmit downlink data destined thereto (step 401 ).
  • the base station Upon receipt of PS-Poll without errors, the base station transmits ACK (step 402 ).
  • the base station also transmits an empty data frame to the terminal station since the base station has not stored data destined to the terminal station (step 403 ).
  • the terminal transmits ACK (step 404 ).
  • the terminal station transitions to a doze state after it has completed the transmission of ACK.
  • FIG. 4B is a sequence chart when data destined to the terminal station is stored in the base station.
  • the terminal station transmits PS-Poll to the base station after it has transitioned to the active mode for requesting the base station to transmit downlink data destined to the terminal station (step 411 ).
  • the base station Upon receipt of PS-Poll without errors, the base station transmits ACK (step 412 ). Since the base station has stored data destined to the terminal station, the base station also transmits a data frame to the terminal station in response to PS-Poll (step 413 ).
  • the terminal station Upon receipt of the data frame without errors, the terminal station transmits ACK (step 414 ).
  • the terminal station transitions to the doze state after it has completed the transmission of ACK.
  • the base station performs the same operation in response to PS-Poll from the terminal station even when the base station has not stored data destined to the terminal station as the operation when the base station has stored data destined to the terminal station, thus permitting the terminal station to transition to the doze state after the completion of a sequential frame exchange procedure (completion of the transmission of the ACK signal).
  • FIG. 5 illustrates a flow chart representing a sequence of operations performed by the terminal station in the processes of FIGS. 4A , 4 B.
  • the terminal station starts a receiving operation, it transitions to the active state (step 501 ).
  • the terminal station transmits PS-Poll to the base station for requesting the base station to transmit data destined to the terminal station (step 502 ).
  • the terminal station determines whether or not it receives ACK which is a response from the base station to PS-Poll (step 503 ). In the event of a failure in receiving ACK, the terminal station again goes to step 502 for transmitting PS-Poll.
  • the terminal station When ACK is successfully received, the terminal station receives data destined thereto, sent from the base station (the data frame received herein includes an empty data frame) (step 504 ). When receiving data, the terminal station transmits ACK to the base station, and transitions to the doze state (step 506 ), followed by completion of the receiving operation.
  • the terminal station may determine whether the base station is a base station conforming to IEEE802.11 (i.e., a base station which only returns an ACK signal in response to PS-Poll from a terminal station when there is no data destined to the terminal station) or a base station which embodies the present invention (i.e., a base station which returns not only an ACK signal but also an empty data frame in response to PS-Poll from a terminal station even when there is not data destined to the terminal station, to select the sequence charts illustrated in FIGS. 3A , 3 B or FIGS. 4A , 4 B.
  • IEEE802.11 i.e., a base station which only returns an ACK signal in response to PS-Poll from a terminal station when there is no data destined to the terminal station
  • a base station which embodies the present invention i.e., a base station which returns not only an ACK signal but also an empty data frame in response to PS-Poll from a terminal station even when there is not data destined to

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Mobile Radio Communication Systems (AREA)
  • Small-Scale Networks (AREA)

Abstract

A power saving method in a wireless LAN system is disclosed for permitting a terminal station to promptly transition to a doze state irrespective of the presence or absence of data destined to the terminal station in a base station. Upon receipt of a PS-Poll signal from a terminal station subordinate to a base station for prompting a transmission of data destined to the terminal station, the base station transmits an ACK signal to the terminal station for indicating a successful reception of the PS-Poll signal. Further, the base station transmits a data frame including data destined to the terminal station when there is such data, or transmits an empty data frame when there is no data destined to the terminal station. Then, upon receipt of the data frame (including the empty data frame), the terminal station transmits an ACK signal to the base station, and then transitions to the doze state in which a transmission/reception function is made inoperative.

Description

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a power saving method in a wireless LAN system, and more particularly, to a power saving method in a wireless LAN system conforming to IEEE802.11.
2. Description of the Related Art
Power saving in a wireless LAN system conforming to IEEE802.11 is performed in sequences illustrated in FIGS. 1A, 1B, for example, as disclosed in IEEE Std 802.11, 9.7 Frame exchange sequences Table 21 Frame sequence.
FIG. 1A is a sequence chart illustrating a sequence of operations when no data destined to a terminal station is stored in a base station. The terminal station transmits PS-Poll, which is a control packet for prompting the base station to transmit data, to the base station for requesting the base station to transmit downlink data destined thereto after the terminal station has transitioned to an active mode, in which a transmission/reception function turns on (step 101). Upon receipt of PS-Poll without error, the base station transmits a successful reception notification signal ACK (step 102). The terminal station transitions to a doze state in which the transmission/reception function turns off after it has completed the transmission of ACK.
FIG. 1B is a sequence chart illustrating a sequence of operations when data destined to the terminal station has been stored in the base station. The terminal station transmits PS-Poll to the base station, after it has transitioned to the active mode, for requesting the base station to transmit downlink data destined thereto (step 111). Upon receipt of PS-Poll without errors, the base station transmits a data frame (step 112). Upon receipt of the data frame without errors, the terminal station transmits ACK (step 113). The terminal station transitions to the doze state after it has completed the transmission of ACK.
FIG. 2 is a flow chart illustrating the operation of the terminal station in the foregoing situation. As the terminal station starts a receiving operation, it transitions to an active state (step 201). Next, the terminal station transmits PS-Poll to the base station for requesting the base station to transmit data destined to the terminal station (step 202). Next, the terminal station determines whether a response to PS-Pall from the base station is ACK or data (step 203). If the terminal station fails to receive either ACK or data, the terminal station again transmits PS-Pall (step 202). Upon receipt of ACK, the terminal station determines that there is no data destined thereto stored in the base station, and transitions to the doze state (step 205). Upon receipt of data, the terminal station transmits ACK to the base station (step 204), and transitions to the doze state (step 205), followed by termination of the receiving operation.
In the foregoing sequence of operations, when data destined to the terminal station is stored in the base station, the base station returns a data frame when it receives the PS-Poll signal from the terminal station without errors. However, conventional general wireless LAN base stations are often configured to return ACK to a terminal station in response to PS-Poll from the terminal station irrespective of the presence or absence of data to the terminal station. This is because it takes long time to complete the transmission of the data frame so that the base station informs, as a temporary measure, the terminal station that the PS-Poll signal has been received without errors. IEEE802.11 also approves that ACK is returned.
FIGS. 3A, 3B illustrate sequence charts when a base station returns ACK to a terminal station in response to PS-Poll from the terminal station irrespective of the presence or absence of data destined to the terminal station.
FIG. 3A is a sequence chart when no data destined to a terminal station is stored in the base station. The terminal station transmits PS-Poll to the base station after it has transitioned to the active mode for requesting the base station to transmit downlink data destined thereto (step 301). Upon receipt of PS-Poll without errors, the base station transmits ACK (step 302).
FIG. 3B is a sequence chart when data destined to a terminal station is stored in a base station. The terminal station transmits PS-Poll to the base station after it has transitioned to the active mode for requesting the base station to transmit downlink data destined thereto (step 311). Upon receipt of PS-Poll without errors, the base station transmits ACK to the terminal station (step 312). When data destined to the terminal station is stored in the base station, the base station further transmits a data frame to the terminal station (step 313). Upon receipt of the data frame without errors, the terminal station transmits ACK (step 314).
In this way, data communications in a power save mode in a general wireless LAN differs in a frame sequence chart between the terminal station and base station depending on the presence or absence of data destined to the terminal station stored in the base station. Then, as illustrated in FIGS. 3A, 3B, when the base station returns ACK to the terminal in response to PS-Poll from the terminal station irrespective of the presence or absence of data destined to the terminal station, the terminal station experiences difficulties in determining whether to transition to the doze state when no data is stored in the base station, resulting in difficulties in a reduction in power consumption. This is because the terminal station cannot determine the presence or absence of data destined thereto at the time it receives ACK, and therefore cannot promptly transition to the doze state. This is because the terminal station does not know whether or not data destined thereto is present in the base station at the time it receives ACK. Therefore, even if there is no data destined to the terminal station, the terminal station cannot transition to the doze state immediately after the receipt of ACK.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a power saving method in a wireless LAN system, which permits a terminal station to promptly transition to the doze state irrespective of the presence or absence of data destined to the terminal station in a base station.
To achieve the above object, in the power saving method of the present invention, upon receipt of a PS-Poll signal from a terminal station subordinate to a base station for prompting a transmission of data destined to the terminal station, the base station transmits an ACK signal to the terminal station for indicating a successful reception of the PS-Poll signal, and also transmits a data frame including data destined to the terminal station when there is such data, or transmits an empty data frame when there is no data destined to the terminal station. Then, upon receipt of the data frame (including the empty data frame), the terminal station transmits an ACK signal to the base station, and then transitions to the doze state in which a transmission/reception function is made inoperative.
As described above, according to the present invention, even when no data destined to a terminal station is stored in a base station, the base station performs the same operation in response to PS-Poll from the terminal station as the operation when data is stored therein, so that the terminal station can transition to the doze state after it has completed a sequential frame exchange procedure, thus making it possible to save the power in the terminal station.
The above and other objects, features and advantages of the present invention will become apparent from the following description with reference to the accompanying drawings which illustrate examples of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A, 1B are sequence charts each illustrating a conventional power saving method in a wireless LAN system conforming to IEEE802.11, where FIG. 1A is a sequence chart when no data destined to a terminal station is stored in a base station, and FIG. 1B is a sequence chart when data destined to the terminal station is stored in the base station;
FIG. 2 is a flow chart illustrating a sequence of operations performed by the terminal station in the processes of FIGS. 1A, 1B;
FIGS. 3A, 3B are sequence charts each illustrating the operation of a base station when it returns ACK to a terminal station in response to PS-Poll from the terminal station irrespective of the presence or absence of data destined to the terminal station, where FIG. 3A is a sequence chart when no data destined to the terminal station is stored in the base station, and FIG. 3B is a sequence chart when data destined to the terminal station is stored in the base station;
FIGS. 4A, 4B are sequence charts each illustrating a power saving method according to the present invention in a wireless LAN system conforming to IEEE802.11, where FIG. 4A is a sequence chart when no data destined to a terminal station is stored in a base station, and FIG. 4B is a sequence chart when data destined to the terminal station is stored in the base station; and
FIG. 5 is a flow chart illustrating a sequence of operations performed by the terminal station in the processes of FIGS. 4A, 4B.
 DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 4A, 4B illustrate sequence charts of a power saving method in a wireless LAN system conforming to IEEE802.11 in accordance with the present invention. Like the operations illustrated in FIGS. 3A, 3B, a base station returns ACK to a terminal station in response to PS-Poll from the terminal station irrespective of the presence or absence of data destined to the terminal station.
FIG. 4A is a sequence chart when no data destined to a terminal station is stored in a base station. The terminal station transmits PS-Poll to the base station after it has transitioned to an active mode for requesting the base station to transmit downlink data destined thereto (step 401). Upon receipt of PS-Poll without errors, the base station transmits ACK (step 402). The base station also transmits an empty data frame to the terminal station since the base station has not stored data destined to the terminal station (step 403). Upon receipt of this empty data frame without errors, the terminal transmits ACK (step 404). The terminal station transitions to a doze state after it has completed the transmission of ACK.
FIG. 4B is a sequence chart when data destined to the terminal station is stored in the base station. The terminal station transmits PS-Poll to the base station after it has transitioned to the active mode for requesting the base station to transmit downlink data destined to the terminal station (step 411). Upon receipt of PS-Poll without errors, the base station transmits ACK (step 412). Since the base station has stored data destined to the terminal station, the base station also transmits a data frame to the terminal station in response to PS-Poll (step 413). Upon receipt of the data frame without errors, the terminal station transmits ACK (step 414). The terminal station transitions to the doze state after it has completed the transmission of ACK.
In the foregoing manner, in this embodiment, the base station performs the same operation in response to PS-Poll from the terminal station even when the base station has not stored data destined to the terminal station as the operation when the base station has stored data destined to the terminal station, thus permitting the terminal station to transition to the doze state after the completion of a sequential frame exchange procedure (completion of the transmission of the ACK signal).
FIG. 5 illustrates a flow chart representing a sequence of operations performed by the terminal station in the processes of FIGS. 4A, 4B. As the terminal station starts a receiving operation, it transitions to the active state (step 501). Next, the terminal station transmits PS-Poll to the base station for requesting the base station to transmit data destined to the terminal station (step 502). Then, the terminal station determines whether or not it receives ACK which is a response from the base station to PS-Poll (step 503). In the event of a failure in receiving ACK, the terminal station again goes to step 502 for transmitting PS-Poll. When ACK is successfully received, the terminal station receives data destined thereto, sent from the base station (the data frame received herein includes an empty data frame) (step 504). When receiving data, the terminal station transmits ACK to the base station, and transitions to the doze state (step 506), followed by completion of the receiving operation.
In another embodiment, when the terminal station comes under the control of a base station, the terminal station may determine whether the base station is a base station conforming to IEEE802.11 (i.e., a base station which only returns an ACK signal in response to PS-Poll from a terminal station when there is no data destined to the terminal station) or a base station which embodies the present invention (i.e., a base station which returns not only an ACK signal but also an empty data frame in response to PS-Poll from a terminal station even when there is not data destined to the terminal station, to select the sequence charts illustrated in FIGS. 3A, 3B or FIGS. 4A, 4B.
While preferred embodiments of the present invention have been described using specific terms, such description is for illustrative purposes only, and it is to be understood that changes and variations may be made without departing from the spirit or scope of the following claims.

Claims (3)

1. A power saving method in a wireless LAN system, comprising the steps of:
determining, from Association Response information received from a base station when a terminal station is subordinate to said base station, whether said base station is a base station capable of transmitting an empty data frame in response to a signal even when said base station does not have data destined to said terminal station;
upon receipt of a signal at said base station from said terminal station subordinate to said base station for prompting a transmission of data destined to said terminal station, transmitting an ACK signal indicative of a successful reception of the signal to said terminal station, and transmitting a data frame including data destined to said terminal station when there is such data, and transmitting an empty data frame when there is no data destined to said terminal station; and
upon receipt of the data frame at said terminal station and only when said terminal station is subordinate to said base station, transmitting an ACK signal to said base station and transitioning to a state in which a transmission/reception function is made inactive.
2. A terminal station in a wireless LAN system, comprising:
first means for transmitting a signal to a base station to which said terminal station is subordinate for prompting a transmission of data destined to said terminal station;
second means responsive to a data frame received from said base station for transmitting an ACK signal to said base station and bringing said terminal station into a state in which a transmission/reception function is made inoperative; and
third means for determining, from Association Response information received from said base station when said terminal station is subordinate to said base station, whether said base station is a base station capable of transmitting an empty data frame in response to signal even when said base station does not have data destined to said terminal station, and operating said second means only when said terminal station is subordinate to such a base station.
3. The terminal station of claim 2, further comprising said base station in a wireless LAN system, the base station comprising means responsive to a received signal from said terminal station subordinate to said base station for prompting a transmission of data destined to said terminal station for transmitting an ACK signal indicative of a successful reception of the signal to said terminal station, and means responsive to the signal received from said terminal station for generating and transmitting a data frame including data destined to said terminal station when there is such data, and for generating and transmitting an empty data frame when there is no data destined to said terminal station.
US11/166,276 2004-06-28 2005-06-27 Power saving method in wireless LAN system for permitting terminal station to promptly transition to doze state by transmitting empty data frame Expired - Fee Related US7391746B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US12/109,536 US20080212508A1 (en) 2004-06-28 2008-04-25 Power saving method in wireless lan system for permitting terminal station to promptly transition to doze state by transmitting empty data frame

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2004-189759 2004-06-28
JP2004189759A JP4032257B2 (en) 2004-06-28 2004-06-28 Power saving method in wireless LAN, base station, terminal station, wireless LAN system

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US12/109,536 Division US20080212508A1 (en) 2004-06-28 2008-04-25 Power saving method in wireless lan system for permitting terminal station to promptly transition to doze state by transmitting empty data frame

Publications (2)

Publication Number Publication Date
US20050286454A1 US20050286454A1 (en) 2005-12-29
US7391746B2 true US7391746B2 (en) 2008-06-24

Family

ID=35505593

Family Applications (2)

Application Number Title Priority Date Filing Date
US11/166,276 Expired - Fee Related US7391746B2 (en) 2004-06-28 2005-06-27 Power saving method in wireless LAN system for permitting terminal station to promptly transition to doze state by transmitting empty data frame
US12/109,536 Abandoned US20080212508A1 (en) 2004-06-28 2008-04-25 Power saving method in wireless lan system for permitting terminal station to promptly transition to doze state by transmitting empty data frame

Family Applications After (1)

Application Number Title Priority Date Filing Date
US12/109,536 Abandoned US20080212508A1 (en) 2004-06-28 2008-04-25 Power saving method in wireless lan system for permitting terminal station to promptly transition to doze state by transmitting empty data frame

Country Status (4)

Country Link
US (2) US7391746B2 (en)
JP (1) JP4032257B2 (en)
CN (1) CN1716894B (en)
TW (1) TWI269545B (en)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070086419A1 (en) * 2005-10-18 2007-04-19 Samsung Electronics Co., Ltd. Method for allocating transmission period in a wireless communication system
US20090077277A1 (en) * 2007-09-17 2009-03-19 Alberto Vidal Methods and apparatus for decreasing power consumption and bus activity
US20090279474A1 (en) * 2008-05-08 2009-11-12 Institute For Information Industry Relay station, base station, power management method, and computer readable medium thereof for use in a wireless mesh network
US20100039971A1 (en) * 2008-08-15 2010-02-18 Hong Kong Applied Science and Technology Research Institute, Co. Power Management Method and Communication System
US20100103955A1 (en) * 2008-10-29 2010-04-29 Cisco Technology, Inc. Power management of a network device
US20100118753A1 (en) * 2008-04-17 2010-05-13 Pmc Sierra Ltd. Power saving in ieee 802-style networks
US20120148246A1 (en) * 2009-08-21 2012-06-14 Mitsubishi Electric Corporation Pon system, subscriber-side terminal apparatus, station-side terminal apparatus, and power saving method

Families Citing this family (32)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7693117B2 (en) * 2002-12-16 2010-04-06 Avaya Inc. Power-saving mechanism for periodic traffic streams in wireless local-area networks
JP2006014167A (en) * 2004-06-29 2006-01-12 Nec Corp Power saving method/program/recording medium for wireless lan, terminal station, and wireless lan system
DK2008391T3 (en) 2006-04-19 2014-04-14 Ericsson Telefon Ab L M METHOD AND APPARATUS FOR IMPROVED DATA COMMUNICATION IN CELLULAR ACCESS SYSTEMS
TWI316374B (en) * 2006-07-21 2009-10-21 Hon Hai Prec Ind Co Ltd System and method for saving power of station
GB0616476D0 (en) * 2006-08-18 2006-09-27 Fujitsu Ltd Communication systems
US8284706B2 (en) * 2007-09-20 2012-10-09 Qualcomm Incorporated Semi-connected operations for wireless communications
JP4907562B2 (en) * 2008-01-08 2012-03-28 株式会社日立製作所 Server, communication apparatus, communication system, and communication method
US8699426B2 (en) 2008-03-26 2014-04-15 Qualcomm Incorporated Method and apparatus for resource allocation in wireless communication systems
CN102016975A (en) * 2008-03-28 2011-04-13 寇平公司 Handheld wireless display device having high-resolution display suitable for use as a mobile internet device
CN101610566B (en) * 2008-06-19 2012-05-30 财团法人工业技术研究院 System and method for dynamically regulating dormant/waking time course of wireless network device
CN101835247A (en) * 2009-03-12 2010-09-15 华为技术有限公司 Method for energy conservation and activation of base station, network device, active device and network system
US8542620B2 (en) 2009-05-05 2013-09-24 Qualcomm Incorporated Dynamic energy saving mechanism for access points
US8705488B2 (en) * 2009-06-17 2014-04-22 Electronics And Telecommunications Research Institute Method for supporting idle mode in wireless local area network system
US8576761B1 (en) * 2009-09-18 2013-11-05 Qualcomm Incorporated Power save delivery mechanism for wireless communication traffic
US8537733B1 (en) 2010-02-12 2013-09-17 Qualcomm Incorporated Dynamic power mode switch in a wireless ad-hoc system
US9311446B1 (en) 2010-03-19 2016-04-12 Qualcomm Incorporated Multicast transmission for power management in an ad-hoc wireless system
US8588156B1 (en) 2010-04-27 2013-11-19 Qualcomm Incorporated Direct data communication in infrastructure mode in wireless communication systems
US8526346B1 (en) 2010-04-28 2013-09-03 Qualcomm Incorporated Power save communication mechanism for wireless communication systems
WO2012011264A1 (en) * 2010-07-21 2012-01-26 日本電気株式会社 Wireless lan communication terminal in wireless lan system, and communication control method for wireless lan communication terminal
US8611268B1 (en) 2011-04-15 2013-12-17 Qualcomm Incorporated Access point power save mechanism for wireless communication systems
US9019986B2 (en) * 2011-11-18 2015-04-28 Futurewei Technologies, Inc. System and method for communications link control
CN103188774B (en) * 2011-12-29 2017-02-08 华为技术有限公司 Method of achieving site sleep, device of achieving site sleep and system of achieving site sleep
KR101481358B1 (en) 2012-02-03 2015-01-09 엘지전자 주식회사 Method for transmitting and receiving frame performed by station operating in power save mode in wireless local area newtork system and appratus for the same
US9049658B2 (en) 2012-03-06 2015-06-02 Qualcomm Incorporated Power save mechanism for peer-to-peer communication networks
CN104335664B (en) * 2012-04-02 2018-04-20 Lg电子株式会社 The method and apparatus that channel is accessed in wlan system
EP2874459B1 (en) * 2012-07-13 2020-03-18 LG Electronics Inc. Method for accessing channel using null data packet in wireless lan system
US20140098727A1 (en) * 2012-10-04 2014-04-10 Apple Inc. Methods and apparatus for network signaling during low-power operation
JP6144934B2 (en) * 2013-03-15 2017-06-07 キヤノン株式会社 Printing apparatus, control method thereof, and program
EP2974426A2 (en) * 2013-03-15 2016-01-20 Intel Corporation Downlink power management
CN105612806A (en) 2013-11-06 2016-05-25 Kt株式会社 Method for transmitting and receiving data in wireless local area network system and apparatus therefor
WO2015069047A1 (en) * 2013-11-06 2015-05-14 주식회사 케이티 Method and device for transmitting and receiving data in wireless lan system
CN108370292B (en) * 2015-10-09 2021-09-03 交互数字专利控股公司 Method and apparatus for efficient acknowledgement transmission

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003517741A (en) 1998-08-14 2003-05-27 テレフォンアクチーボラゲット エル エム エリクソン（パブル） Method and apparatus for power saving in mobile terminal establishing connection
JP2004104465A (en) 2002-09-10 2004-04-02 Sharp Corp Communication device and terminal station
US20050136833A1 (en) * 2003-12-19 2005-06-23 Emeott Stephen P. Unscheduled power save delivery method in a wireless local area network for real time communication

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB9304638D0 (en) * 1993-03-06 1993-04-21 Ncr Int Inc Wireless data communication system having power saving function
WO2000068907A1 (en) * 1999-05-06 2000-11-16 Pinpoint Corporation An asset and personnel tagging system utilizing gps
US6275500B1 (en) * 1999-08-09 2001-08-14 Motorola, Inc. Method and apparatus for dynamic control of talk groups in a wireless network
EP1342339A2 (en) * 2000-12-08 2003-09-10 Telefonaktiebolaget LM Ericsson (publ) Method for power save in a mobile terminal
US7551948B2 (en) * 2003-07-24 2009-06-23 Cisco Technology, Inc. Uniform power save method for 802.11e stations
US7471664B2 (en) * 2005-11-02 2008-12-30 Intel Corporation Network management policy and compliance in a wireless network

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003517741A (en) 1998-08-14 2003-05-27 テレフォンアクチーボラゲット エル エム エリクソン（パブル） Method and apparatus for power saving in mobile terminal establishing connection
JP2004104465A (en) 2002-09-10 2004-04-02 Sharp Corp Communication device and terminal station
US20050136833A1 (en) * 2003-12-19 2005-06-23 Emeott Stephen P. Unscheduled power save delivery method in a wireless local area network for real time communication
JP2007515903A (en) 2003-12-19 2007-06-14 モトローラ・インコーポレイテッド Unscheduled power saving transmission method in wireless local area network for real-time communication

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
IEEE Standard for Information technology-Telecommunications and information exchange between systems-Local and metropolitan area networks-Specific requirements, "Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications", ANSI/IEEE Std 802.11, 1999 Edition, pp. 95-136.

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070086419A1 (en) * 2005-10-18 2007-04-19 Samsung Electronics Co., Ltd. Method for allocating transmission period in a wireless communication system
US8068476B2 (en) * 2005-10-18 2011-11-29 Samsung Electronics Co., Ltd. Method for allocating transmission period in a wireless communication system
US20090077277A1 (en) * 2007-09-17 2009-03-19 Alberto Vidal Methods and apparatus for decreasing power consumption and bus activity
US8473647B2 (en) * 2007-09-17 2013-06-25 Apple Inc. Methods and apparatus for decreasing power consumption and bus activity
US8275261B2 (en) * 2008-04-17 2012-09-25 Pmc Sierra Ltd Power saving in IEEE 802-style networks
US20100118753A1 (en) * 2008-04-17 2010-05-13 Pmc Sierra Ltd. Power saving in ieee 802-style networks
US20090279474A1 (en) * 2008-05-08 2009-11-12 Institute For Information Industry Relay station, base station, power management method, and computer readable medium thereof for use in a wireless mesh network
US8116329B2 (en) * 2008-05-08 2012-02-14 Institute For Information Industry Relay station, base station, power management method, and computer readable medium thereof for use in a wireless mesh network
US20100039971A1 (en) * 2008-08-15 2010-02-18 Hong Kong Applied Science and Technology Research Institute, Co. Power Management Method and Communication System
US7903597B2 (en) 2008-10-29 2011-03-08 Cisco Technology, Inc. Power management of a network device
US20100103955A1 (en) * 2008-10-29 2010-04-29 Cisco Technology, Inc. Power management of a network device
US20120148246A1 (en) * 2009-08-21 2012-06-14 Mitsubishi Electric Corporation Pon system, subscriber-side terminal apparatus, station-side terminal apparatus, and power saving method
US9106984B2 (en) * 2009-08-21 2015-08-11 Mitsubishi Electric Corporation PON system, subscriber-side terminal apparatus, station-side terminal apparatus, and power saving method

Also Published As

Publication number Publication date
US20050286454A1 (en) 2005-12-29
US20080212508A1 (en) 2008-09-04
CN1716894B (en) 2010-04-21
JP4032257B2 (en) 2008-01-16
CN1716894A (en) 2006-01-04
TWI269545B (en) 2006-12-21
TW200610300A (en) 2006-03-16
JP2006014028A (en) 2006-01-12

Similar Documents

Publication Publication Date Title
US7391746B2 (en) Power saving method in wireless LAN system for permitting terminal station to promptly transition to doze state by transmitting empty data frame
US7133398B2 (en) System and method for asynchronous communications employing direct and indirect access protocols
CN101305624B (en) System and method for detecting an unlicensed mobile alliance (UMA) service in GSM wireless communication networks
US8161302B2 (en) Method and apparatus for data transmission in wireless local access network and system therefor
US8406699B2 (en) Method and apparatus for reducing the load of managing the power save state of a partner
US6934566B2 (en) Wireless communication device and controlling method thereof
KR102404017B1 (en) State switching method and apparatus
US8116329B2 (en) Relay station, base station, power management method, and computer readable medium thereof for use in a wireless mesh network
TWI498023B (en) Communications apparatus and method for reducing power consumption of a communications apparatus in wlan system
US20060079232A1 (en) Wireless LAN handover method, wireless terminal, program product for use in the wireless terminal, and wireless communications system
CN110089164A (en) The energy-saving mode of improved wireless device
US20070129093A1 (en) Power management methods and systems
EP1503545B1 (en) Method and apparatus for controlling power consumption of stations on CSMA/CA-based wireless LAN
US8559366B2 (en) Method of communication, emitter and receiver stations and associated computer programs
US20160119864A1 (en) Method and apparatus for connecting portable terminal to wlan
US7174161B2 (en) Radio communication apparatus and radio communication method
US8953568B2 (en) Roaming method and apparatus for terminals in wireless local area network
US20100054166A1 (en) Apparatus and method for controlling idle mode of mobile station in a wireless communication system
US8054771B2 (en) Method and system for adding a new connection identifier to an existing power save class
JP4670457B2 (en) Wireless LAN terminal, wireless LAN system, and state transition method
US8396017B2 (en) Apparatus and method for filtering broadcast message
KR20070037866A (en) Method for power efficiency management in the wireless lan
KR20090047597A (en) Apparatus and method for power saving mode support in broadband wireless access system
JP2008048429A (en) Method for saving power in wireless lan, base station, terminal station, wireless lan system
US20100105450A1 (en) Apparatus and method for reducing power consumption of mobile station in wireless communication system

Legal Events

Date Code Title Description
AS Assignment

Owner name: NEC CORPORATION, JAPAN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:MORIMOTO, SHINICHI;KUROKAWA, HIDEKI;OMORI, YOUKO;REEL/FRAME:016732/0349

Effective date: 20050613

STCF Information on status: patent grant

Free format text: PATENTED CASE

FPAY Fee payment

Year of fee payment: 4

FPAY Fee payment

Year of fee payment: 8

FEPP Fee payment procedure

Free format text: MAINTENANCE FEE REMINDER MAILED (ORIGINAL EVENT CODE: REM.); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

LAPS Lapse for failure to pay maintenance fees

Free format text: PATENT EXPIRED FOR FAILURE TO PAY MAINTENANCE FEES (ORIGINAL EVENT CODE: EXP.); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

STCH Information on status: patent discontinuation

Free format text: PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362

FP Expired due to failure to pay maintenance fee

Effective date: 20200624